Pour the coconut cream into a pot and set it on low heat.
Tie the pandan leaves (as seen in the video tutorial) and add them to the pot.
Add the salt, followed by the sugar, and stir until fully dissolved.
Let simmer and remove from heat. Set aside to cool.
Red Rubies / Tub Tim Krob
Place the diced water chestnut in a large bowl.
Add the liquid red food color and water to it and mix well. Set aside for 10 minutes so that the water chestnut absorbs the color.
In the meantime, bring about 3 cups of water to a boil.
Once the water chestnut has absorbed the water, place the tapioca flour in another large bowl. Add the colored water chestnut to it and mix with a spoon, making sure that all sides are evenly coated.
With a slotted spoon, take some coated water chestnut and sift to remove the excess flour. Do not use a flour sifter in this step as the holes are too tiny to remove any lumps.
Throw the water chestnut into boiling water and cook until floating.
Prepare a large bowl of iced or cold water.
When the water chestnut is floating, it means the rubies are cooked. Simply use the same slotted spoon to transfer the rubies to the bowl of iced water to stop it from cooking.
Equally split the rubies into 6 dessert bowls and pour the coconut syrup over them. Tub tim krob is often enjoyed with crushed ice in Thailand so you can add some ice to each bowl. Remember that the ice will dilute the coconut syrup so make sure the syrup is sweet enough if you are serving this dessert with ice.
The rubies are best eaten within the day of making. Stored in light syrup in the fridge, they will keep for about 2 days but will not taste as good, and the tapioca layer will start to fall off.